Vehicles typically include cabin vents or pressure relief devices. Without such devices, air pressure inside a vehicle cabin could damage ear drums of occupants of the vehicle. Further, when a vehicle door is closed, air pressure within the vehicle needs to be relieved or the door typically is unable to fully close. If an air bag is deployed in a vehicle that does not have a venting or pressure relief device, ear drums of an occupant of the vehicle could be damaged.
Pressure relief devices are usually hidden from view. For example, a pressure relief device may be found in a trunk or on a body frame pillar structure. Each pressure relief device is adapted to allow air to pass out of an enclosed structure, while also preventing a significant amount of air, dust, water or other contaminants from passing into the enclosed area. Thus, pressure relief devices are, in essence, one-way valves that are configured to maintain a small amount of back pressure.
A pressure relief device may include a plastic main body having a plurality of air passages. A light membrane flap, such as formed of sanoprene, foam material, or the like, is positioned over each air passage, and is configured to allow air to pass in one direction. In order to allow air to pass, the light membrane flap opens off of the main body in response to air flow. Typically, a seal is provided around the main body and acts to seal the hole in the mating structure upon assembly. The seal is typically molded around the main body in a secondary molding operation, or may be adhesively or chemically attached to the main body.
During installation, the pressure relief device may be snap fit to a structure. Typically, an installer presses on the four corners of the pressure relief device in order to secure the pressure relief device within a reciprocal hole in a structure, such as a vehicle frame.
Typical pressure relief devices may produce noise during operation. For example, when a membrane flap is urged open, the membrane flap may produce an undesired flapping sound.